Thursday, July 30, 2015

We are interested in the application of interactive storytelling to videogames. We want to improve story experiences in open-world adventure and role-playing games. A game that features an open world allows its players to move freely in a large space with few or no artificial barriers, choosing what to do and when. The flexibility of an open world and the fact that adventure and role-playing games tend to have strong story components make these genres an interesting place to explore interactive storytelling techniques.

Our central goal is to support the creation of open-world videogame stories that give players a sense of coherence. To achieve this, we take a structuralist approach and partition stories into two types of scenes inspired by the concept of kernelsandsatellites. First, a minimal set of fixed scenes form a core story with strong authorial control. A game’s most central plot points become fixed scenes, thus acting like kernels. The rest of the story emerges from a much larger collection of flexible scenes that can appear just about anywhere in story save a small set of preconditions. Most flexible scenes act like satellites: minor plot points, or opportunities to develop story elements like theme.

We want to give players the freedom to explore flexible scenes however they wish as they move through the fixed scenes as designed. A certain level of coherence is guaranteed when the content of the fixed scenes is itself coherent, but a story with few satellite scenes will have minimal aesthetic appeal. The challenge, then, is to maintain coherence no matter how a very large set of flexible scenes is experienced.

Instead of arranging flexible scenes according to a strict definition of causal coherence, we want to create a “sense of” coherence. By this we mean that not all events have to be causally related in explicitly obvious ways, but that players should have the sense that they could figure out the meaning of and relationships between events if they thought hard enough about it.

One of the major ways we achieve a sense of coherence is by managing the story’s progression. We keep track of when certain story elements, such as theme and character, are reflected. We then prioritize which scenes should be made available to players next according to a desired distribution of the story elements. For example, if a particular theme was developed very recently, we want to prioritize scenes that reflect some of the other themes. On the other hand, if it has been a long time since a theme was developed, scenes that reflect that theme strongly should have high priority. A good distribution of elements ensures that story elements don’t feel out of place when developed, and that reminders of previous scenes are made throughout the story.

Another facet of creating a sense of coherence is the emergence of structure at run-time through the use of conditions. Instead of defining causal relationships in a scene graph a priori, we allow authors to define prerequisites for their scenes. Using prerequisites is a common technique, but in our design we push for prerequisites based on story state values in addition to game state. For example, scenes might have prerequisites that only allow them to be seen once a particular theme has been developed sufficiently. Alternatively, a scene might be best suited for the early development of the theme, and should not appear later on. We want authors to think about flexible scenes in terms of how they function in a story’s development without having to worry about how they will fit within a series of causally related events.

In addition to controlling the path players take through a set of fixed and flexible scenes, we can improve the sense of coherence by adjusting the content of scenes. In so doing, we want to give players interpretative agency: they should feel like there are deeper layers in the story not being explicitly told, and they should feel like they can interpret those layers in a reasonable way.

We are exploring three ways of dynamically affecting the content of scenes. In the first, run-time criteria is used to choose a set of scenes that a recurring motif (say, an apple) can be featured in. Observant players will begin to notice the motif over time and assign meaning to why it appears in certain scenes. Eventually, they will expect something in particular to happen when a new scene with the motif begins.

Second, mix-ins give us pre-scripted opportunities to make connections to scenes the player happens to have already seen. As Keith Johnstone points out in the context of improvisation, “feeding something back in from earlier in the story adds ‘point’ and creates structure.” Characters, story elements, and dialog are all examples of source material that could be referred to in future mix-ins.

Finally, we can adjust the presentation of a scene to alter the player’s interpretation of otherwise unchanging events. Choice of lighting, background music, camera angles, and even the weather can all depend on the story’s state at the time a particular scene is reached. Perhaps the heroine of the story returns to the castle with the head of a dragon. The mood evoked during the scene might be bright and cheerful if the player saw the dragon as an evil menace. However, the mood might be more sombre if the player found out that the dragon was simply a loving mother trying to protect her hatchlings. The final event stays the same, but the interpretation of it changes.

In summary, our goal is to give players a sense of coherence when exploring stories in open-world adventure and role-playing games. We structure our stories as a set of fixed and flexible scenes. Players can traverse the set of flexible scenes freely, barring any prerequisites that deem certain scenes inaccessible. Flexible scenes are prioritized so that story elements are well distributed throughout the story. We encourage interpretative agency by dynamically introducing recurring motifs, using mix-ins to make connections to earlier points in the story, and modifying the presentation of a scene to affect interpretation. Through all of this, higher quality open-world stories will emerge while still maintaining a satisfactory level of interactivity.

Wednesday, July 22, 2015

I had a great time at this year's Foundations of Digital Games, but it was the talks and the hallway track with narrative folks that really left me inspired. In this post I'll summarize the first three keynotes and some inspiration I got from one of them; you can check out my raw talk notes and the proceedings for more details. The sketch notes I'm including are all by Chris Martens, a fellow narrative PhD candidate (though she'll be done soon!).

Tom Forsyth's Keynote

The first keynote of the conference was given by Tom Forsyth, who worked at Valve and then Oculus VR. Tom highlighted some of the challenges we face when designing all-new experiences for virtual reality. For example, motion sickness comes from there being an imbalance between what your eyes see and what your ears feel, so having players move up stairs causes issues (elevators are apparently much better). It's also important to avoid most cinematography techniques, and to use an eye blink transition whenever possible.

The next day we heard from Robin Hunicke, who produced Journey and is seriously inspirational. She began by talking about Wattam and its designer Keita's inspiration for the game. The zaniness levels of that game are right up my alley, making me want to get a PS4 even more...

Most of Robin's talk was about her inspiration for Luna, which as she puts it, was kind of a beast. She talked in depth about the inspiration noted on the game's website: "origami, shadow boxes, abstract sculpture and minimalist illustration." Near the beginning of the design process, she apparently spent six months alone in her apartment, folding paper. It turned out that folding paper digitally wasn't very fun, but that didn't mean some of the lessons learned from origami couldn't apply to a game's design. Luna looks wonderfully whimsical, and I am hoping I was mistaken about it being a VR game (or at least, not VR-exclusive) because I would really like to try it.

The first academic keynote of the conference, R. Michael Young is in charge of the Liquid Narrative Group at NCSU. He described some of the main areas his group looks at in the world of narrative after reminding us that "narrative is big. Really big."

The systems his group builds are evaluated based on whether they produce narratives that can be understood by humans in particular ways. They break narrative down into story (everything that happens inside the story world), discourse (the choices the author makes in how to tell the stories; what goes into the telling), and interactivity (what happens when a player goes into the role of a character? How do we design the story and discourse?).

The group's most used tool seems to be artificial-intelligence-based planners. Planning looks at how to automatically sequence actions in the face of a novel set of environmental goals. In narrative, this might mean anything from having characters scheme to achieve their own goals, to authors planning to mislead then reveal. Stories are broken down into the smallest possible units (such as individual actions), then built back up. Many problems arise from the use of standard planners, which often tell uninteresting stories. One of the ways to improve the outcomes is the group's current work in progress that attempts to express character traits through the action sequences created.

Michael's distinction between story and discourse got me thinking about my own thesis project (read a somewhat out-of-date description here). I realized that a large part of what I'm doing feels more like discourse than story.

It felt even more clear to me when I thought about Mieke Bal's definitions of story and fabula from Narratology: Introduction to the Theory of Narrative. A fabula is "a series of logically and chronologically related events that are caused or experienced by actors" while a story is "a fabula that is presented in a certain manner." Most of the techniques I am working on actually don't affect the fabula so much as the way the fabula is experienced.

One of the areas I struggled with in my thesis proposal was justifying why I didn't want to use planners. There are some definite reasons that were easy to articulate, such as difficult authoring. However, I also had this unarticulated understanding that planners weren't quite right for the design approach I took, but wasn't sure exactly why.

By thinking about story and fabula, I was able to realize that I'm not trying to arrange actions into a story so much as allow navigation through a set of coarser story pieces featuring fixed actions. I want players to be able to explore a mostly fixed fabula in different ways, leading to different interpretations of it. In the process, the resulting story should still have a sense of (but not necessarily actual) coherence.

As a result of this insight and another cool idea that came up during the conference, my thesis project's focus is tightening up very nicely. I'll share more about that sometime in the future.

Sunday, July 19, 2015

During the last full week of June, I took a wonderful trip to Pacific Grove, California for Foundations of Digital Games 2015. (You might recall that last year's conference was on a cruise ship.) I didn't end up presenting anything this year, and I'm so glad I went despite this. I found the whole experience rather invigorating.

This year's conference was held at Asilomar Conference Grounds, which began life as a YWCA summer camp for girls about 100 years ago. It is part of Asilomar State Beach, which is, unsurprisingly, gorgeous.

Our keynotes and some of the parallel track sessions were held in the site's chapel. Not the greatest for lighting (and, to an extent, sound), but a really neat building in terms of its architecture.

All meals were held in the dining hall at a set time signalled by the dinner bell. In addition to giving meals a fun summer camp feel, it ensured that everyone in the conference ate together. I loved this setup for its ability to build community and encourage networking. I had many excellent conversations over food, and even some pivotal moments in terms of my thesis (more on that in a future post). A downside was that the food was usually just ok at best, and there was always too much of it .

Although most attendees stayed on site, we were spread around many different buildings on site. I was really surprised to see our lodging when I first walked up to it. I remember describing it as a "70's nature lodge" and wondering how something so dated, and without any in-room phones or TVs, could cost so much. I suppose, though, that a lot of the money goes towards the maintenance of the beach, which softens the blow. It really did grow on me over time; the slight ocean view from the balcony likely didn't hurt.

One of the things I really enjoyed was walking along the boardwalks that wound through the protected sand dunes. They were often higher than the beach, thus affording some lovely views. Occasionally, you even met some wildlife along the way.

After the conference was over, I headed to Monterey and spent an afternoon at Monterey Bay Aquarium with a fellow conference attendee. The aquarium is inside old cannery buildings, so from the outside doesn't look like much. It was absolutely spectacular inside, though. I loved every minute there and could have stared at some of the exhibits forever, constantly discovering new details.

After a long walk along the coast to my last hotel room and an early morning flight the next day, my trip was over. I can't say I've ever had a bad experience travelling to California, and I'm really grateful that I was able to use my professional development money at Carleton to make this trip. Stay tuned for a future post about the academic side of FDG.